The measurement accuracy of precision measurement instruments, such as oscilloscopes, is subject to such conditions as ambient temperature changes, power supply voltage fluctuations, and aging of electronic components.
Many attempts have been made to increase and maintain measurement accuracy, such as using stabilized DC power supplies, temperature-compensated components where appropriate, and low-power, integrated microcircuits for signal processing.
Typically, overall accuracy for long-term instrument operation is specified at 3% over a wide temperature range, such as 0.degree. C. to +50.degree. C. Enhanced accuracy, e.g., 1% accuracy, may be attained in some instruments for a short time immediately following calibration, provided that the instruments remains operating, and all of the other variables (e.g., ambient temperature, etc.) remain constant. However, the actual length of this short time period is indeterminable, and therefore, such enhanced accuracy may not be suitable for long-term experiments or display photography.